Visible light communication

About: Visible light communication is a research topic. Over the lifetime, 8672 publications have been published within this topic receiving 106943 citations.

Visible light communication using OFDM

Abstract: In this paper wireless communication using white, high brightness LEDs (light emitting diodes) is considered. In particular, the use of OFDM (orthogonal frequency division multiplexing) for intensity modulation is investigated. The high peak-to-average ratio (PAR) in OFDM is usually considered a disadvantage in radio frequency transmission systems due to non-linearities of the power amplifier. It is demonstrated theoretically and by means of an experimental system that the high PAR in OFDM can be exploited constructively in visible light communication to intensity modulate LEDs. It is shown that the theoretical and the experimental results match very closely, and that it is possible to cover a distance of up to one meter using a single LED.

An Indoor Visible Light Communication Positioning System Using a RF Carrier Allocation Technique

Abstract: We propose a new indoor positioning system utilizing visible light communication. Intensity modulation/direct detection and carrier allocation methods are utilized in the proposed system. Simultaneous three channel transmissions were applied to calculate the receiver's position. The characteristics of the proposed positioning system were investigated through simulation based on the experimental results, and the feasibility of the proposed system was verified by experimentation. The experimental result shows that the average error of estimated positions is reduced to 2.4 cm using adjustment process by normalizing method, which is compared with 141.1 cm without adjustment process.

TDOA-based optical wireless indoor localization using LED ceiling lamps

Abstract: We propose an optical wireless indoor localization using light emitting diodes (LEDs) and demonstrate it via simulation. Unique frequency addresses are assigned to each LED lamp, and transmitted through the light radiated by the LED. Using the phase difference, time difference of arrival (TDOA) localization algorithm is employed. Because the proposed localization method used pre-installed LED ceiling lamps, no additional infrastructure for localization is required to install and therefore, inexpensive system can be realized. The performance of the proposed localization method is evaluated by computer simulation, and the indoor location accuracy is less than 1 cm in the space of 5m x 5 m x 3 m.

Image-sensor-based visible light communication for automotive applications

Abstract: The present article introduces VLC for automotive applications using an image sensor. In particular, V2I-VLC and V2V-VLC are presented. While previous studies have documented the effectiveness of V2I and V2V communication using radio technology in terms of improving automotive safety, in the present article, we identify characteristics unique to image-sensor-based VLC as compared to radio wave technology. The two primary advantages of a VLC system are its line-of-sight feature and an image sensor that not only provides VLC functions, but also the potential vehicle safety applications made possible by image and video processing. Herein, we present two ongoing image-sensor-based V2I-VLC and V2VVLC projects. In the first, a transmitter using an LED array (which is assumed to be an LED traffic light) and a receiver using a high-framerate CMOS image sensor camera is introduced as a potential V2I-VLC system. For this system, real-time transmission of the audio signal has been confirmed through a field trial. In the second project, we introduce a newly developed CMOS image sensor capable of receiving highspeed optical signals and demonstrate its effectiveness through a V2V communication field trial. In experiments, due to the high-speed signal reception capability of the camera receiver using the developed image sensor, a data transmission rate of 10 Mb/s has been achieved, and image (320 × 240, color) reception has been confirmed together with simultaneous reception of various internal vehicle data, such as vehicle ID and speed.

A Comparative Survey of Optical Wireless Technologies: Architectures and Applications

Abstract: New high-data-rate multimedia services and applications are evolving continuously and exponentially increasing the demand for wireless capacity of fifth-generation (5G) and beyond. The existing radio frequency (RF) communication spectrum is insufficient to meet the demands of future high-data-rate 5G services. Optical wireless communication (OWC), which uses an ultra-wide range of unregulated spectrum, has emerged as a promising solution to overcome the RF spectrum crisis. It has attracted growing research interest worldwide in the last decade for indoor and outdoor applications. OWC offloads huge data traffic applications from RF networks. A 100 Gb/s data rate has already been demonstrated through OWC. It offers services indoors as well as outdoors, and communication distances range from several nm to more than 10 000 km. This paper provides a technology overview and a review on optical wireless technologies, such as visible light communication, light fidelity, optical camera communication, free space optical communication, and light detection and ranging. We survey the key technologies for understanding OWC and present state-of-the-art criteria in aspects, such as classification, spectrum use, architecture, and applications. The key contribution of this paper is to clarify the differences among different promising optical wireless technologies and between these technologies and their corresponding similar existing RF technologies.